Given the outright similarity in appearance to 106, and the "interdimensional" mention, one has to wonder if 106 was an inspiration for this guy. (Though this work is obviously original and non-derivative in its current form, not saying anything like that.)

I initially thought this was a generic "scary pitch-black Nyarlathotep" type. Then we saw the mutilation. And how whatever that thing is is clearly *hunting him*. And then the end..daaayum. That has Foundation written all over it and inside it.

Yep. If it proceeded to make dimensional holes in walls that it traveled through and/or decayed things that it touched, THEN I would flat out accuse it of being derivative of 106. But as it is, it's just very Foundation-y in feel, and awesome.